Well, I didn't want this to turn in to an anti or pro ethanol discussion, but it appears it has moved in that direction. Since Gus keeps qualifying my experience as a chassis engineer into "passing along things I have heard", let me please explain a few facts followed by what those mean to us.

Fact 1 - A gallon of gasoline has approx. 116,000 BTU of energy. A gallon of ethanol has approx. 76,000 BTU of energy. So ethanol has approx 2/3 the energy content of a gallon of gasoline.

Fact 2 - Both gasoline and ethanol are hygroscopic meaning they absorb water. Gasoline can disolve 150 ppm of water. A 10% enthanol blend can disolve 6000 ppm of water.

Fact 3 - Phase seperation occurs when moisutre content reaches approx 0.5%

Fact 4 - Pure ethanol has an octane of 113

Fact 5 - Natural rubber compounds are permeable to ethanol.

What I have stated above isn't hearsay or internet BS. Its science. Hopefully you agree with me to this point. Now I will explain what this means in an automotive application.

1. Since ethanol has only 2/3 the energy content of gasoline, its only a suitable replacement (in terms of cost only) if the % of ethanol added results in a cost that is 2/3 of the gasoline that is replaced.

2. Since ethanol has a higer octane than gasoline, a lower octane gasoline can be used because (at least in the US) they use an average octane level when advertising at the pump. So to have say 87 octane gasoline with 10% ethanol, 84 octane base gasoline can be used. With higher % of ethanol, lower octane base fuel can be used. Now the reason this is important is with the higher hygroscopic quality of ehtanol, the gasoline gets dilluted with water which is 0 octane. This causes 2 things. It dillutes the octane of the overall fuel approx 1% for every %of moisture absorbed into the (in this case 10%) ethanol. This results in overall lower octane. Secondly, after the ethanol abosrbs approx 0.5% water, it starts to lose its ability to bond with the gasoline molecules. This is called phase seperation. If this happens, you end up with 3 independent fluids in your tank. A layer of ethanol on top (specific gravity is approx. 0.76), followed by a layer of gasoline (SG 0.78) then at the bottom is the water that has been absorbed (SG 1.0). (Think of how oil floats on top of water in a spill). Since the pickup in the fuel tank pulls from the bottom of the tank, it is pulling the pure water into the lines. This is what leads to the corrosion issues in the steel tank and lines. Not to mention what can happen if the engine tries to compress water. In a sever case, you can end up with a hydrolock engine (admittedly so, this would be a very severe case and not the majority).

3. The fact that nartural rubbers are permeable to ethanol means that ethanol molecules will migrate between the rubber molecules (in a natural rubber hose). This acts to age harden a hose leaving it dry and cracked. You will see charts that show that ethanol doesn't result in swelling of a natural rubber hose, that is because it is not being caught in its molecular structure, but actually passing through it.

So what it comes down to is application. Ethanol is just fine if the materials are selected appropriately. Nitrile rubber (NBR)has been the rubber compound of choice in the auto industry since the mid 80s. Fuel injection lines and marine application lines have different compounds. These make them compatible with the ethanol. Most new cars have plastic fuel tanks and all flex fuel lines will have stainless steel lines. If you continously use the ethanol, it doesn't have the chance to absorb the water and you don't have any issues with corrosion. But most of our cars aren't daily drivers. As far as your heating systems, think about the application. Was it an outdoor application like a car is? Does the ethanol sit for long periods of time (my car has the same fuel in the tank from 2 months ago). Also, what were the hoses made out of? There are thousands of discrete rubber compounds. Each one is tailored to a particular use. This isn't that far fetched. Think about it in other car terms. If you put Type F transfluid in a GM trans or P/S unit, you will most likely destroy the seals. Use the mineral oil from R-12 in a R-134a system that uses ester oil, and you will destroy the o-rings. That's becuase these rubber based components use compounds that are designed for it. I'm sure the hoses that are in your heating system are designed for alcohol use.

Again, my interpretation is based on the science I put forth in the "facts" above. If you dispute the facts, we will have to just agree to disagree. If you dispute my interpretation, we can discuss further.

I am not being led by the oil companies. I am using my experience as an former automotive engineer and my education with a master's in automotive engineering from the University of Michigan to explain my stance.

Ethanol is the devil....if used in the wrong application. Just like gasoline would be the devil if it was used in the wrong application. Or steam, etc. etc. This doens't make me pro or anti ethanol as a whole, but I am definatley anti ethanol in my Firebird. I use a blended fuel in my daily driver when the relative price makes it worth while. I hope I have been able to explain the facts and my interpretation based on those facts without making this into a political discussion.